1. Field
The following description relates to a motor having an improved structure capable of achieving an enhancement in durability.
2. Description of the Related Art
A motor is a machine to obtain rotating force from electrical energy. Such a motor includes a stator and a rotor. The rotor is configured to co-operate with the stator in an electromagnetic manner. The rotor is rotated by a force exerted between a magnetic filed and current flowing through a coil.
Permanent magnet motors, which use permanent magnets to generate an electric field, may be classified into a surface mounted permanent magnet motor, an interior type permanent magnet motor, and a spoke type permanent magnet motor.
The spoke type permanent magnet motor may generate high power with high torque in that it exhibits high magnetic flux concentration. The spoke type permanent magnet motor may also be advantageous in that it may be miniaturized, as compared to other types of motors, for the same output power. The spoke type permanent magnet motor may be applied to drive motors for washing machines or electric vehicles, which require high power with high torque.
Generally, the rotor of the spoke type permanent magnet motor includes permanent magnets arranged about a rotating shaft in a radial manner, and a body to support the permanent magnets while defining passages for magnetic flux. The body may include cores each arranged between adjacent ones of the permanent magnets, and cylindrical supports each arranged between the rotating shaft and a corresponding one of the permanent magnets while being connected to a corresponding one of the cores.
In such a spoke type permanent magnet motor, the cores of the rotor may be deformed or damaged due to centrifugal force generated during high-speed rotation of the rotor because the body of the rotor is weak in terms of structure.
Furthermore, in the spoke type permanent magnet motor, magnetic flux may partially leak toward the rotating shaft through the cylindrical supports of the rotor body. When leakage of magnetic flux increases, the use rate of the permanent magnets may be increased, as compared to other types of motors, for the same motor power. In this case, accordingly, there may be disadvantages in terms of material costs and motor miniaturization.